alien ware (now owned by dell) and falcon are prob. the best off the shelf rigs. but your gonna pay for them through the nose and butt.
If you like gaming, and you really don't want to build one, then head for the alienware and fork over the bucks.
But if you can just hang with it for a day or so, building your own can just really make life so easy. I have been working on computers since the TSR (trash 80) III, timex-sinclair, and vic 20. I have a water cooled rig sitting in storage waiting for my house to be finished. Its a total gaming rig but its not cheap. But it freekin flies. I can run Oblivion at max settings and it wont even breath hard. Im not in to shooters so I have not run anything else, but when Oblivion first came out it was eating machines left and right.
take the time. its well worth it.
Coolermaster 830 Evolution Nvidia Edition Case
Coolermaster 850 PSU
Evga 680i MB
QX6700 Extreme Quad Core
Corsair Dominator DNX PC8500 (4gig)
BFG Factory Cooled GTX8800
HT Omega Striker 7.1 Sound Card (since the board does not support front case mic)
WD Raptor 150 Sata
WD Caviar 160 Sata
Plextor PX775SA DVD reader writer yada yada yada
4 Papst 18db fans
1 Coolermaster 20db fan
The rig is Dual Loop cooled w/
Loop 1: Black Ice Extreme GTX 240 rad with a D5 variable speed pump Vid and Southbridge (680i modified Danger Den Block on the southbridge) Rad under the case using factory holes
Loop 2: Black Ice Extreme GTX 120 rad with a D5 variable speed pump, Quad Core and Northbridge (standard 680i Danger Den block on the northbridge) Rad goes through the MB tray and is attacked to the case fan knock out of the MB tray
gonna get a cooling system update as Danger Den has new stuff. Also will be better cable management. This was just a pre test and I got lazy and left it. It still rocks.